How many boxes fit in a box: nesting calculator
Enter the small box and the big box dimensions — the calculator tries all six orientations, computes an orthogonal packing (the way warehouses actually pack), shows the rows-and-layers scheme and the volume fill. Wall thickness and clearance are accounted for. New in v3.2: add up to four different small-box sizes — type 1 takes the best block, the rest fill the remaining space; the big box comes with presets of common cartons.
Dimensions in centimetres. Everything runs in your browser — no data is sent anywhere.
Master carton done — now price the shipment. The BTRANS team will quote LCL or container freight for your cartons and route.
Get a quote at BTRANSHow to use it
The small box is entered by its outer dimensions — it goes inside whole. The big box has two modes: "inner dimensions" (if you know the usable space, e.g. from a carton spec) and "outer + wall" — the calculator subtracts two wall layers per dimension; regular corrugated board is 3–4 mm per wall, double-wall is 6–7 mm. "Gap per box" adds clearance to each dimension of the small box — set 2–5 mm if boxes go in tight or need to come out freely.
What it computes — and what it doesn't
The calculator computes an orthogonal packing in a single orientation — straight rows and layers, the way real warehouses pack. A mixed packing (some boxes sideways, some upright) occasionally fits a couple more, but that's a 3D-tetris answer nobody reproduces on a real packing line. The numbers shown are an honest practical maximum.
What the nesting calculation accounts for
Wall thickness
The usable space inside a box is smaller than its outer size by two walls per dimension. Regular single-wall corrugated board (B or C flute) is 3–4 mm per wall; double-wall (BC) is 6–7 mm. The "outer + wall" mode subtracts these layers automatically; if you have a carton spec with inner dimensions, enter them directly in "inner" mode.
Nesting gap
A box that fits exactly goes in with a fight and never comes back out. A 2–5 mm gap per dimension leaves room for hands and the imperfect geometry of real cartons. For soft packaging — bags and pouches — you can skip the gap.
How to compute it by hand
Divide each inner dimension of the big box by the matching dimension of the small one, drop the fraction, multiply the three numbers. Repeat for all six orientations of the small box and take the maximum — exactly what the calculator does. Orientation matters: a 30×20×10 box turned different ways yields a different count, and the best option is not always obvious by eye.
Reference box sizes
Common corrugated and mailing formats for a quick estimate:
| Format | Outer size | Use |
|---|---|---|
| Mailing S | 17 × 12 × 9 cm | small goods, accessories |
| Mailing M | 26 × 17 × 10 cm | books, clothing |
| Mailing L | 34 × 24 × 15 cm | footwear, mid-size goods |
| Cube 20 | 20 × 20 × 20 cm | general purpose |
| Carton #15 | 40 × 30 × 25 cm | consolidated parcels |
| Master carton | 60 × 40 × 40 cm | wholesale packing on a pallet |
Sizes are indicative and differ by carton maker. Inner dimensions are always smaller than outer ones by the wall thickness.
FAQ
How do I compute it manually?
Divide each inner dimension of the big box by the matching dimension of the small one, drop the fraction, multiply the three numbers. Repeat for all six orientations and take the maximum — exactly what this calculator does.
What is the wall thickness of a carton?
Single-wall corrugated board (B/C flute) is about 3–4 mm per wall; double-wall (BC) is 6–7 mm. The calculator subtracts two layers per dimension — walls on both sides.
Why do I need a gap?
An exact-size box goes in with a fight and never comes out. A 2–5 mm gap per dimension leaves room for hands and imperfect geometry. For soft packaging (bags) you can skip the gap.
Is weight considered?
No — geometry only. Check the bottom strength and weight limit in your carton spec; for shipment volume and freight use our cargo volume calculator.
Can I mix boxes of different sizes?
Yes. Click “add a box of another size” — up to four sizes. List order is priority: type 1 is packed in its best orientation, the next ones fill the remaining space. The “Qty” field caps a type at the number you have — handy to check whether your whole set fits.
Is weight considered in the nesting calculation?
No — geometry only. How many boxes fit says nothing about whether the bottom holds their weight. Check the load limit and bottom strength in your carton spec. For shipment weight and volumetric weight use our cargo volume calculator and volumetric weight calculator.
Can I mix boxes of different sizes?
Yes, up to four sizes. List order is priority: type 1 is packed in its best orientation, the rest fill the remaining space. The "Qty" field caps a type at the number of boxes you actually have — handy to check whether the whole batch fits.
Why doesn't the calculator turn some boxes sideways?
It computes an orthogonal packing in a single orientation — straight rows and layers, the way warehouses really pack. A mixed packing (some boxes on their side, some upright) occasionally fits a couple more, but that's a 3D-tetris answer nobody reproduces on a real packing line. The numbers shown are an honest practical maximum.
Embed this calculator
Free to embed on packaging, fulfilment and e-commerce sites — two lines of code:
<div id="acm-box-calc" data-brand="CoolVolume" data-brand-url="https://coolvolume.com/en/boxes/"></div> <script src="https://coolvolume.com/widgets/box-fit-calc.en.js" defer></script>